1. Charges at Work Section 10.3

2. Lightning
Charge is transferred between raindrops in a storm cloud. Ions, which are charged atoms or groups of atoms that have gained or lost more than one electron, are formed.

3. Lightning
1) Air currents in the storm cloud cause charge separation. The top of the cloud becomes positive, and the bottom becomes negative 2) Negative charges on the bottom of the cloud induce a positive charge on the ground below the cloud by repelling negative charges in the ground 1 2

4. 3) When the bottom of the cloud has accumulated enough negative charges, the attraction of the positive charges below causes electrons in the bottom of the cloud to move toward the ground. 3 4
4) When the electrons get close to the ground, they attract positive ions that surge upward, completing the connection between the cloud and the ground. This is the spark that you see as a lightning flash.

5. How Lightning Rods Work
A metal sphere attached to the highest part of a building and connected to the ground
It will reduce the likelihood of a strike and, in the event of a strike, conduct the charge safely to the ground

6. Electric Precipitator
A type of cleaner that removes unwanted particles and liquid droplets from a flow of gas
Can be effective in reducing pollution from smokestacks

7. Electrostatic Spray Painting
Paint is given a charge when it leaves the nozzle of the sprayer
The object to be painted (car) is either grounded or given the opposite charge
Particles of paint are attracted to the object, minimizing the amount of over-spray

8. Van de Graaff Generator
Is a device that can accumulate and transfer very large charges
Inside the column is a belt moving over rollers creating a charge through friction
The belt delivers the charge to the comb

9. Photocopiers & Laser Printers

10. Photocopiers & Laser Printers

11. Radiation Dosimeter
A small device that detects and measures exposure to radiation
Worn by people who work with radioactive materials

12. Questions Page 421 #1, 2, 4 Page 426 #6 & 8